Examples for how to code nice looking (function) spreadsheets in Latex

Spreadsheets.tex

\documentclass[a4paper]{article}

\usepackage{colortbl} % Defines \columncolor, \multicolumn
\usepackage{pgfplots} % Defines lightgray

\newcolumntype{g}{>{\columncolor{lightgray}}c}
\newcolumntype{f}{>{\columncolor{pink}}c}
\newcommand{\col}[1]{\multicolumn{1}{c|}{#1}}

\begin{document}

A $5 \times 5$ identity matrix:
\begin{tabular}{|g|c|c|c|c|c|c|}
  \hline
  \rowcolor{lightgray}
   & \col{A} & \col{B} & \col{C} & \col{D} & \col{E} & \col{F} \\ \hline
 1 & \texttt{1} & \texttt{0} & \texttt{0} & \texttt{0} & \texttt{0} & \\ \hline
 2 & \texttt{0} & \texttt{1} & \texttt{0} & \texttt{0} & \texttt{0} & \\ \hline
 3 & \texttt{0} & \texttt{0} & \texttt{1} & \texttt{0} & \texttt{0} & \\ \hline
 4 & \texttt{0} & \texttt{0} & \texttt{0} & \texttt{1} & \texttt{0} & \\ \hline
 5 & \texttt{0} & \texttt{0} & \texttt{0} & \texttt{0} & \texttt{1} & \texttt{= A1:E5} \\ \hline
\end{tabular}

Recursive function to compute the sum of the Fibonacci sequence up to some $n$:
\begin{tabular}{|f|c|c|}
  \hline
  \rowcolor{pink}
    & A                                 & B                      \\ \hline
  1 &                                   & \texttt{= FIB(A1 - 1)} \\ \hline
  2 & \texttt{= IF(A1 = 1, 1, B1 + B2)} & \texttt{= FIB(A1 - 2)} \\ \hline
  3 & \texttt{= IF(A1 <= 0, 0, A2) }    & \texttt{= DEFINE(``FIB'', A3, A1)} \\ \hline
\end{tabular}

\end{document}